MAKING REAMERS AND BARREL REAMING

This is the most important part of making the rifle barrel. If you don't have a true and smooth bore, you
don't have anything. I will show you how to make reamers for finishing the barrels. On barrel reamers,
you will need two reamers. One a rough reamer for removing and cleaning up the drilled bore, and the
finish reamer to take the bore to the correct size.

INFORMATION ON REAMERS

Reamers are made with both straight and helical flutes. The latter provided a shearing cut and are
especially useful in reaming holes having key ways or grooves. These are bridged over by the helical
flutes, thus preventing binding or chattering. Hand reamers are made in both solid and expansion forms.

SHAPE OF FLUTES

Style and shape of the flute determine its ability to carry away chips and the relative strength of the tooth.
For manufacturing, a straight shank may be used. With fluting reamers, the cutter is so set about to the
center of the reamer blank so the tooth gets a slight negative rake, the amount is so selected that a
tangent to the circumference of the reamer at the cutting point makes an angle of about 95 degrees with
the front face of the cutting edge.

When fluting reamers, it is necessary to break up the flute, which means to space the cutting edges
uneven around the reamer. The difference in spacing should be very slight and need not to exceed
about .004 either way.

The manner, which you use to break up the flutes, is if the reamers are made on a mill is to set the cutter
anywhere from .002 to .004 in front of the center of the reamer blank, and changing it a .001 or so on
each flute.